[ntp:questions] Very large jitter and offsets on GPS ref clock after upgrade to "p5"

David J Taylor david-taylor at blueyonder.co.uk.invalid
Wed Jan 11 07:36:37 UTC 2012


"unruh" <unruh at invalid.ca> wrote in message 
news:7Y2Pq.10307$xs3.7567 at newsfe17.iad...
[]
> No, I was talking about the width of the edge transition. Neither the
> accuracy of that transition, nor the width of the pulse. the former one
> cannot know unless one has another gps whose accuracy one knows, and the
> latter is irrelevant to timekeeping. However the post I was replying to
> almost certainly was talking about the width of the pulse, not the width
> of the transition. Note that the gamin has a pulse width that is quite a
> bit less than 1usec. What its accuracy is I do not know.

Please be more careful in your terminology.  The width of the Garmin GPS 
18(x) LVC pulse is nominally 100 milliseconds, not "bit less than 1usec". 
You will be confusing people who haven't worked with this kit.  You almost 
had me believing that the Oncore had a pulse with of 1 microsecond (which 
sounded wrong, but....).

The Garmin 18x is specified: "1 microsecond accuracy [under normal 
conditions]"

Cheers,
David
 



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